Find the mean deviation about the mean for the data.

The following table is formed.

Here, $N=\sum_{i=1}^{8} f_{i}=50, \sum_{i=1}^{8} f_{i} x_{i}=17900$

$\therefore \bar{x}=\frac{1}{N} \sum_{i=1}^{s} f_{i} x_{i}=\frac{1}{50} \times 17900=358$

M.D. $(\bar{x})=\frac{1}{N} \sum_{i=1}^{8} \mathrm{f}_{i}\left|\mathrm{x}_{i}-\bar{x}\right|=\frac{1}{50} \times 7896=157.92$